Many types of surgical and dental appliances are secured to the bone of the patient using bone screws, or other elongate fasteners. Bone nails or wires, usually supported by external or internal frames, e.g., the widely used Kirschner wire type devices are also commonly used.
One of the major problems the surgeon faces is the drilling of holes in the right location, properly spaced from each other and properly oriented relative to each other. Problems have been encountered in the past, for example, in drilling holes to receive bone fastening devices, i.e., devices to secure an appliance to the bone, such as bone screws, pins, wires and the like and in forming cavities for dental implants with a sufficient degree of precision, orientation and spacing.
Such holes, bores, recesses or passages are traditionally formed freehand. Of course, this can readily result in defective bores. There is a danger that the bore will be at such an inclination or position that the spongiosa or cortical bone or associated vascular or nerve tissue will be excessively damaged. Failure to maintain precision and spacing with respect to this dimension may be the cause of a variety of problems. Bone grafting or other procedures may be required to compensate for improper orientation or positioning of the implant cavity in the bone. Sometimes, once the damage has been caused, complete repair is not possible.
When the appliance is subjected to loading and when the screws or implants, for example, are not properly oriented there may be an element of transverse pressure transmission to the implant or fastener which can produce secondary infections and may lead to failure of the implant or fastener.
A feature of this invention is the provision of a quick, highly accurate, and inexpensive method and means for assuring proper spacing and orientation of holes to be drilled in a patient's bone to receive implants, screws, or other bone fasteners.